Treatment of phenols



- --PatentedMar.13,1945

Universal Oil Products Company, Chicago, 111., a corporation of Delaware No Drawing.

10' Claims.

This application is a continuation-impart of my copending application Serial No. 391,099, filed This invention relates to the treatment of phenols. to produce alkylated phenols. More specifically it is concerned with theproduction of monoalkylated and poly-alkylated phenols in the presence of a catalyst.

- It is recognized .that in general the catalytic alkylation of phenols has been known for some time. However, the present invention difierem tiates from the prior art on this subject in the use of a particular catalytic material comprising as its active. ingredient an acid phosphate of an alkaline earth metal.

The phenols constitute an important class of chemical compounds which occur in varying amounts in the products obtained when distilling various carbonaceous materials such as coal, shale, lignite, peat, wood, etc. Many of these individual compounds and the commercial mix- Alkylated phenols or mixturesthereof, such as produced by the process of the present invention, may'be utilized as inhibitors, insecticides, germicides, etc., and as intermediates in the synthesis of dyes, resins, etc.

In one specific embodiment the present. invention comprises a process for producing alkylated phenols which comprises subjecting a phenol and 'an olefinic hydrocarbon to contact under alkylating conditions in the presence of a catalyst comprising as its active ingredient an acid phosphate of an alkaline earth metal.

Phenols which are alkylatable by o'leflnic hy- Application February 20, 1942, Serial No. 431,661

(or. zoo-s24) April 30, 1941, now-Patent No. 2,290,211, July 21, 1942.

to the alkylation of certain substituted phenols such as bromo-phenols,-chloro-phenols, aminophenols, etc., although not necessarily under the same conditions of operation utilizable with the unsubstituted phenols themselves. Many monoalkylated phenols may be converted into more highly alkylated phenols by the process of this invention.

Olefinic hydorcarbons utilizable as alkylating agents in the present instance comprise monoolefins and poly-olefins. Olefins which are employed in the present process are either normally gaseous or normally liquid and comprise ethylene and its higher homologs, both gaseous and liquid, the latter including various polymers of normally gaseous oleflns, but these difierent olefinic hydrocarbons and those mentioned hereinafter are not necessarily equivalent in their action as allwlating agents. Cyclic oleflns may also serve in alkylatingphenols but generally under conditions of operation different from those employed when alkylating phenols by non-cyclic olefins.

Other oleflnic hydrocarbons which may be interacted with the above indicated phenolsinclude u conjugated dioleiins such as butadiene and isodrocarbons and olefin-producing substances as hereinafter set forth have at least one hydroxy groupattached directly to a benzene ring. The

. term phenol as used in this specification and in the claims relates to any of a series of hydroxyl prene, also nod-conjugated diolefins, and other poly-olefins. Oleiinic hydrocarbons utilizable as alkylating agents are present in products of thermal and catalytic cracking of oils, in those obtained by dehydrogenating paraflinic and oleflnic hydrocarbons or in the products resulting from dehydrating alcohols. Alkylation of phenols may also beefiected in the presence of catalysts hereinafter described by charging with the phenol a substance capable of producing olefinic hydrocarbons under the op-' erating conditions chosen for the reaction. Such olefin-producing substances which contain an allr'oxy group include alcohols, ethers, and esters, which are capable oi undergoing dehydration or splitting to oleflnic hydrocarbons, containing at least two carbon atoms per molecule, which may be consideredas present in the reaction mixture even though possibly as transient intermediate produce desired alkylation products.

Catalysts suitable for use in eflecting the proccalcium salt or 'ortho phosphoric acid is repre- The process or this invention is also applicable as sented by the formula Ca(HzPO4)z-HzO for the hydrated salt' or as Ca(HzlO4)z'when--water of compounds which react further with phenols to hydration is absent. An acid salt of an acid of phosphorus and of an alkaline earth metal may be used as such or it may be mixed with or deposited upon carriers or supporting materials such as silica, diatomaceous earth, alumina, silica-alumina composites, crushed porcelain, pumice, firebrick, etc.

A composite of an alkaline earth acid phosphate and a carrier in ilnely powdered form, after tho'r-. ough mechanical mixing, may be subjected to drying, pelleting, and heating operations to produce formed particles of catalyst suitable for use as reactor packing material, or the alkaline earth acid phosphate itself may be similarly formed into pellets or granules. A suitable carrier may also be impregnated with a selected acid phosphate to form a composite catalyst suitable for use in promoting interaction of phenols and ole- .ilnic hydrocarbons. A suitable catalytic material may be prepared by adding to di-calcium-phosphate or tri-calcium phosphate the calculated amount of ortho-phosphoric acid to form a. composite with a composition corresponding to that of mono-calcium phosphate. Thus addition of phosphoric acid to an alkaline earth phosphate forms a catalyst of desired alkylating activity, but in general an acid phosphate containing no free phosphoric acid has sufficient activity for catayzlni; the process as herein described. The different alkylating catalysts which may be employed in the present process are not necessarily equivalent in their action.

Further, when an acid phosphate is used in connection with a carrienthe proportions of carrier and active ingredient may be variedas desired to make catalyst composites of diiierent activities. Accordingly, catalytic material of appropriate activity is thus available for use with normal, secondary, and tertiary oleflns, the latter generally being the most reactive.

There isrelatively little formation of carbon or carbonaceous material upon the preferred types of catalysts when the. reactions between phenols and oleflnic hydrocarbons are carried out under hydrogen pressure, but carbon iormation does occur to a substantial extent in the absence of hydrogen.

In effecting reaction between phenols 'and an alkylating agent such as an oleilnio hydrocarbon according to the process oi'the present invention,

the exact method of procedure varies with the nature of the reacting constituents. A simple procedure, utilizable in the case of a phenol which is normally liquid, or it solid is readily soluble or easily dispersible in a substantially inert liquid. and a normally gaseous or liquid oleflnic hydrocarbon, consists in contacting the phenol and oleiinic hydrocarbon with a catalystcontaining an acid phosphate of an alkaline earth metal at a temperature of from about 100 to about 450 C. and preferably between about 250 and about 400 C, under a pressure up to about 200 atmospheres or more. Intimate contact of the reacting components with the catalyst is eflected by passing the reaction mixture through a fixed bed of granular or pelleted catalyst or the reactin components may be mixed with finely divided catalyst and reacted in either a batch or continuous type of operation. The materials subjected to reaction are preferably in the propor- 'tion of 1 molecular proportion of clefinic hydrocarbons to between about 2 and about molecular proportions oi phenols in order to diminish polymerization oi oleflnic hydrocarbons and to iavor calcium acid phosphate, or at least a portion of Thus a mixture comprising essentially a phenol and a fraction containing oleflnic hydrocarbons are commingled and passed through a reactorcontaining an acid phosphate such as monothe phenolic material is charged to such a reactor while the fraction containing olefinic hydrocarbons, as such or preferably diluted by another portion of the phenol being treated, is introduced at various points between the inlet and outlet of the reaction zone in such a way that the reaction mixture being contacted with the catalyst will at all times contain a relatively low proportion of the olefinic hydrocarbon and thus favor interaction of phenols and oleflnic hydrocarbons rather than polymerization of the latter. The

phenol being treated may be in liquid ormolten condition or it may be dissolved or dispersed in a substantially inert liquid as a liquid parailln hydrocarbon fraction.

While the method of passing the phenols and the circumstances such as the temperature, presi sure, and activity oi the catalyst found to be most efiective for producing the desired reaction between particular phenols and oleflnic hydrocarbons. i

Alkaline earth acid phosphates as herein described permit continuous reaction of phenolic compounds and oleflnic hydrocarbons in the presence of a fixed bed of catalyst and thus make it possible to avoid mechanical problems as well as oxidation and corrosion difliculties encountered when this reaction is carried out in the presence of sulfuric acid which is sometimes used as an alkylating catalyst. Further, an acid phosphate such as calcium acid phosphate also has the advantage over aluminum chloride utili'zable for the same purpose in that an acid phosphate forms substantiallyno addition compounds or complexes with phenols and/or oleiinic hydrocarbons as is characteristic of catalysts containing aluminum chloride.

Reactions between oleflnic hydrocarbons and phenols in the presence of an alkaline earth acid phosphate are apparently 0! a relatively simple character although they may be accompanied by certain amounts of decomposition or destrucbond 0! an 'oleflnic' hydrocarbon to produce an alkylated phenol which may in turn undergo further reaction with 1 or more molecular proportlons oi cleflnic hydrocarbon thus producing dithealkylating agent is a diolefln or other polyoleiin. the interaction with a phenol may involve not only alkylation but possibly polymerization. Thus phenol and butadiene may give a substantial yield of butenyl phenols which polymerize. Within certain limits, however, it is possible to produce mainly mono-alkylated phenols by proper adjustment oi catalyst activity, ratio of phenol to .olefinic hydrocarbons, operating conditions of temperature, pressure, rates of feed of the reacting components, etc.

The reaction between a phenol and a hexene or other normally liquid olefin of higher molecular 2.8 cc. of higher boiling material. The total of 9.9 cc. of material boiling between 214 and 240 'C. contained substantial amounts of ortho-isopropylphenyl-isopropylether which boiled between 222 and 230 C.

A comparative run on phenol and propylene" product and the phenol charged was recovered weight may involve not only addition of phenol r and oleflnic hydrocarbons but also a depolymerization or splitting of .the oleflnic hydrocarbon into oleflnic fragments of lower molecular weights which react with the phenolic compound to produce alkylated phenols. Thus phenol and diisobutene or tri-isobutene react and yield tertiary butyl phenol and poly-tertiary butyl phenols,

while nonene and phenol yield both butyl and amyl' phenols by so-called depoly-aikylation.

In general, the products formed by interaction of an oleflnic hydrocarbon with a molal excess or a phenol are separated from the unreacted phenol by suitable means as by distillation, and the un-.

reacted portion of the phenol originally charged and generally the poly-alkylated phenols formed are returned to the process and mixed with additional quantities of the oleflnic hydrocarbons and phenol being charged to contact with the catalyst. This recycling or poly-alkylated phenols sometimes aids in theproduction oi mainly mono-alkylated phenols and depresses the formation of more highly alkylated derivatives. The

stricting the generally broad' scope of the invention.

81 grams of phenol, grams of propene, and 10 grams oi mono-calcium phosphate were intromally gaseous oleflnic hydrocarbon to contact at unchanged. l

The nature of the present invention and it commercial utility can be seen from the specification and example given, although neither section is intended to limit its generally broad scope.

I claim as my invention:

l. A process for producing alkylated phenols which comprises reacting a phenol with an oleflnic hydrocarbon at a temperature of from about 100 C. to about 450 C. in the presence of a catalyst comprising essentially an acid phosphate of an alkaline earth metal.

2. A process for producing alkylated phenols which comprises subjecting a phenol and an oleflnic hydrocarbon to contact at a temperature of from about 100 to about 450C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of a catalyst comprising essentially an acid phosphate or an alkalineearth metal.

3. A process for producing ,alkyiated phenols which comprises subjecting a phenol anda nora temperature or from about 100 to about 450 C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of a catalyst comprising essentially an acid phosphate of an alkaline earth metal.

4. A process for producing alkylated phenols which comprises subjecting a phenol and a normally liquid oleflnic hydrocarbon to contact at a temperature of from about 100 to about 450 C. under a pressure of from substantially atmosduced to a rotatable autoclave of 850 cc. capacity and placed under an' initial nitrogen pressure of atmospheres. The autoclave and contents were then heated for 4 hours at 300 C. under a maximum pressure of 110 atmospheres.

After the reaction and when the autoclave had.

cooled to room temperature the reaction mixture was removed from the autoclave and separated. into 9'7 grams of liquid product and 10.5 grams of white catalyst powder. The liquid prodwt was further separated into an alkali-soluble and an alkali-insoluble portion by extracting an pheric to approximately 200 atmospheres in the presence of a catalyst comprising essentially an acid phosphate of an alkaline earth metal.

.5. A process for producing alkylated phenols which comprises subjecting a phenol and an oleflnic hydrocarbon to contact at -a temperature 1 oi from about 100 to about 450 C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of a catalyst comprising essentially a calcium acid phosphate.

other solution thereof with several'portio'ns of an aqueous solution containing 10% oi sodium hydroxide. solved phenolic compounds was acidified with bydrochloric acid, then extracted with ether, and the ether extract was dried and distilled. This distillationseparated the purified phenolic compounds into 38 cc. of unreacted phenol which 4.7 cc. boiling between 225 C. and 240' C., and

The alkaline solution containing an crystallized on standing, 6.2 cc. 0! an intermediate traction boiling between 190 and 213 C., 18.1

6. A process for producing alkylated' phenols. which comprises subjecting a phenol andan oleflnic hydrocarbon to contact at a temperature of from about to about 450 C. under a pressure of from substantially atmospheric to approximately 200 atmospheres in the presence of a catalyst comprising essentially calcium dihydrophosphate.

"I. A process for producing alkylated phenol which comprises subjecting phenol and an oleflnic hydrocarbon to contact at a temperature 01' from about 100 to about 450 C. under a pressure of from substantially atmospheric toapproximately 200 atmospheres in the presence iii a catalyst comprising essentially calcium dihydrophosphate.

8. A process for producing ethylated phenol which comprises subjecting phenol and. ethylene to contact at a temperature oi from about 100 to about 450 C. under a pressure of from substantially atmospheric to approximately 200 at- 'mospheres in the presence of a catalyst compris ing essentially calcium dihydrophosphate.

pheres in the presence of a cataiyst comprising essentially calcium dihydrophosphate. 10. A process for producing alkylated phenols 4 aansso which comprises subjecting a phenol and an oleflnic hydrocarbon to contact at a temperature of from about 100 to about 450 C. in the presence of a. catalyst comprising essentially a composite of an acid phosphate of an alkaline earth metal and a substantially inert carrier.

RAYMOND E. 

